In many cases, external components such as a shock absorber interposed between sprung and unsprung members of a vehicle are operated while they are exposed to the external air at all times. Pollutants such as dust, dirt, or muddy water are attached to the external components such as a shock absorber used in the exposed state in this manner.
If pollutants such as dust, dirt, or muddy water are attached to a sliding portion in a rod that moves into and out of a cylinder, the pollutants may hinder lubrication of the sliding portion or promote deterioration of a sealing member used to seal the sliding portion. For this reason, a dust boot is provided in the external components such as a shock absorber in order to protect the sliding portion from dust, dirt, or the like.
More specifically, the dust boot has a tubular boot body partially provided with a bellows portion and a flange portion provided in an upper end of the boot body. The dust boot covers the sliding portion of the rod that moves into and out of the cylinder at all times by extending or contracting the bellows portion. As a result, the sliding portion of the rod is isolated from the outside of the dust boot and is protected from adhering of pollutants such as dust, dirt, or muddy water.
The dust boot is fixed to the shock absorber or the like by holding the flange portion between a suspension spring seat connected to a tip side of the rod of the shock absorber or the like and a suspension spring configured to bias the shock absorber or the like to an expansion direction (for example, see JPH11-264433 A).